The invention relates to a pressure-actuated valve as set forth herein. The pressure-actuated valve includes a valve body that is actuated in the closing direction toward a valve seat by a spring element. Once the valve body is seated on its valve seat, a flow opening is closed, and a chamber containing pressure on the inflow side is separated from a chamber containing pressure on the outflow side.
Depending on the pressure difference between that on the inflow side and that on the outflow side, the valve body can close the flow opening; that is, the valve body covers the flow opening. The pressure on the inflow side acts upon the valve body in the region of the flow opening. The part of the valve body that covers the flow opening represents an effective pressure face for the inflow-side pressure. If the inflow-side pressure attains a certain value, this pressure can lift the valve body from the valve seat, counter to the closing force of the spring element, and pressure fluid can flow out of the first chamber into the second chamber. If a large flow of pressure fluid from the first chamber into the second chamber is intended to be possible, without overly throttling the flow of pressure fluid in the region of the flow opening, then the flow opening must be correspondingly large. If the flow opening is large, then in order that the spring element acting upon the valve body can close the flow opening, the spring element must be dimensioned accordingly. The larger the flow opening, the stronger the spring element has to be in order to be capable of keeping the inflow-side pressure at a desired value.
In the known pressure-actuated valve, if high pressures are to be protected against, without causing excessive throttling of the flow of pressure fluid when the flows are larger, then a strong spring element is necessary, which results in a very large, massive pressure-actuated valve.
In this known valve, the pressure fluid can flow only out of one certain chamber into the other. With this sole possible flow direction, the pressure-actuated valve functions as a so-called pressure holding or pressure limiting valve or safety valve. In the known valve, a flow in the opposite direction is not possible.